/**************************************************************************/
/*                                                                        */
/*       Copyright (c) Microsoft Corporation. All rights reserved.        */
/*                                                                        */
/*       This software is licensed under the Microsoft Software License   */
/*       Terms for Microsoft Azure RTOS. Full text of the license can be  */
/*       found in the LICENSE file at https://aka.ms/AzureRTOS_EULA       */
/*       and in the root directory of this software.                      */
/*                                                                        */
/**************************************************************************/


/**************************************************************************/
/**************************************************************************/
/**                                                                       */
/** NetX Component                                                        */
/**                                                                       */
/**   Internet Group Management Protocol (IGMP)                           */
/**                                                                       */
/**************************************************************************/
/**************************************************************************/

#define NX_SOURCE_CODE


/* Include necessary system files.  */

#include "nx_api.h"
#include "nx_packet.h"
#include "nx_igmp.h"
#include "nx_ip.h"
#include "tx_thread.h"



/**************************************************************************/
/*                                                                        */
/*  FUNCTION                                               RELEASE        */
/*                                                                        */
/*    _nx_igmp_packet_receive                             PORTABLE C      */
/*                                                           6.1          */
/*  AUTHOR                                                                */
/*                                                                        */
/*    Yuxin Zhou, Microsoft Corporation                                   */
/*                                                                        */
/*  DESCRIPTION                                                           */
/*                                                                        */
/*    This function handles reception of IGMP packets on the "all hosts"  */
/*    multicast address.  If this routine is called from an ISR, the      */
/*    IGMP packet is queued.  Otherwise, if this routine is called from   */
/*    the IP helper thread, the processing of the IGMP packet is called   */
/*    directly.                                                           */
/*                                                                        */
/*  INPUT                                                                 */
/*                                                                        */
/*    ip_ptr                                IP instance pointer           */
/*    packet_ptr                            IGMP packet pointer           */
/*                                                                        */
/*  OUTPUT                                                                */
/*                                                                        */
/*    None                                                                */
/*                                                                        */
/*  CALLS                                                                 */
/*                                                                        */
/*    _nx_igmp_packet_process               Process the IGMP packet       */
/*    tx_event_flags_set                    Set event flags for IP helper */
/*                                            thread                      */
/*                                                                        */
/*  CALLED BY                                                             */
/*                                                                        */
/*    _nx_ip_packet_receive                 Raw IP packet receive         */
/*                                                                        */
/*  RELEASE HISTORY                                                       */
/*                                                                        */
/*    DATE              NAME                      DESCRIPTION             */
/*                                                                        */
/*  05-19-2020     Yuxin Zhou               Initial Version 6.0           */
/*  09-30-2020     Yuxin Zhou               Modified comment(s),          */
/*                                            resulting in version 6.1    */
/*                                                                        */
/**************************************************************************/
VOID  _nx_igmp_packet_receive(NX_IP *ip_ptr, NX_PACKET *packet_ptr)
{

TX_INTERRUPT_SAVE_AREA


#ifndef NX_DISABLE_RX_SIZE_CHECKING

    /* Check for valid packet length.  */
    if (packet_ptr -> nx_packet_length < sizeof(NX_IGMP_HEADER))
    {

#ifndef NX_DISABLE_IGMP_INFO
        /* Increment the IGMP invalid packet error.  */
        ip_ptr -> nx_ip_igmp_invalid_packets++;
#endif

        /* Invalid packet length, just release it.  */
        _nx_packet_release(packet_ptr);

        /* The function is complete, just return!  */
        return;
    }
#endif

    /* Determine if this routine is being called from an ISR.  */
    if (TX_THREAD_GET_SYSTEM_STATE())
    {

        /* If non-zero, we are in an ISR.  Just place the message on the
           IGMP message queue and wakeup the IP helper thread.  */

        /* Disable interrupts.  */
        TX_DISABLE

        /* Add the packet to the IGMP message queue.  */
        if (ip_ptr -> nx_ip_igmp_queue_head)
        {

            /* Link the current packet to the list head.  */
            packet_ptr -> nx_packet_queue_next =  ip_ptr -> nx_ip_igmp_queue_head;
        }
        else
        {

            /* Empty queue, add to the head of the IGMP message queue.  */
            packet_ptr -> nx_packet_queue_next =  NX_NULL;
        }

        /* Update the queue head pointer.  */
        ip_ptr -> nx_ip_igmp_queue_head =  packet_ptr;

        /* Restore interrupts.  */
        TX_RESTORE

        /* Wakeup IP thread for processing one or more messages in the IGMP queue.  */
        tx_event_flags_set(&(ip_ptr -> nx_ip_events), NX_IP_IGMP_EVENT, TX_OR);
    }
    else
    {

        /* The IP message was deferred, so this routine is called from the IP helper
           thread and thus may call the IGMP processing directly.  */
        _nx_igmp_packet_process(ip_ptr, packet_ptr);
    }
}

